Piston stroke adjusting arrangement for disc-type friction clutches and brakes

ABSTRACT

A piston stroke adjusting arrangement for disc-type friction clutches or brakes used most advantageously in forging machines and presses where rapid engagement and disengagement of clutches and brakes is essential. The arrangement includes a housing and a cylinder flange, fast with each other, the cylinder receiving the piston reciprocating therein. Axial displacement of the piston is limited by a washer arrangement in a groove made in the housing and having radially running recesses of different depths. The flange of the cylinder carries an abutment engageable in one of the radial recesses of the washer. The disclosed construction simplifies the structure of the arrangement, as a whole, and provides for both rapid and reliable adjustment of the piston stroke value.

This is a continuation of application Ser. No. 810,288 filed June 27,1977 now U.S. Pat. No. 4,176,738

BACKGROUND OF THE INVENTION

The invention relates to disc-type friction clutches and brakes and,more particularly, it relates to arrangements for adjusting the strokeof the actuating piston in such clutches and brakes.

The invention can be used to utmost effectiveness in both the existingforging machines and presses and those being built, since rapidity ofengagement and disengagement of the clutches and brakes in such machinesand presses is essential.

More often than not the existing arrangements for adjusting the strokeof a piston include washers.

Two commonly known types of such arrangements are available. The firsttype is one including two washers of which the first, acting as thepiston-washer, has stepped radially through recesses. The other washerlikewise has stepped recesses so that this washer can be centeredrelative to the piston-washer by engagement of the external surface ofthe piston-washer with the internal surface of the stepped recesses ofthe second washer. Adjustment of the piston stroke value is effected byrotating one of the washers relative to the other one, which has provedto be a time-consuming operation. The washers are retained in anadjusted position with aid of a locking device of which one part islocated on the external surface of the cylinder receiving thepiston-washer, and the other part is carried by the second washer. Theincorporation of the locking device complicates the structure of theentire apparatus. Moreover, sophisticated machinery is to be used in themanufacture of washers with stepped recesses.

The other type of adjusting arrangements includes a washer with radialrecesses of different depths, accomodated between a housing and a flangeof, a cylinder receiving a piston reciprocating therein, the housing andthe cylinder being rigidly secured to each other, the stroke of thepiston being limited by the washer (see, for example, Swiss Pat. No.376,728, Cl. 47 c; 9, issued in 1964). In this last-described type ofthe arrangement adjustment of the piston stroke is carried out,similarly to the first-described type of the arrangement, by rotatingthe cylinder flange about its own axis, which brings about considerabledifficulties in cases where the brake or the clutch are of largedimensions. Furthermore, the rotation of these bulky parts is atime-consuming operation. Moreover, in the last-described apparatus ofthe prior art bushes and bolts are incorporated to secure the washer tothe housing, which complicates the structure of the arrangement, as awhole, and hampers the operations of mounting and removing the washerwhen the friction linings of the brake or of the clutch become worn out.

SUMMARY OF THE INVENTION

It is an object of the present invention to create a piston strokeadjusting apparatus which should speed up the adjustment process.

It is another object of the present invention to simplify the structureof the arrangement.

It is still another object of the present invention to provide forfacilitated maintenance of the arrangement.

These and other objects are attained in a piston stroke adjustingarrangement for disc-type friction clutches and brakes, comprising awasher with a plurality of radial recesses of different depths,accomodated between a housing and a flange of a cylinder receivingtherein a reciprocating piston, the housing and the flange being rigidlyattached to each other, and the piston having its axial displacementlimited by said washer, wherein, in accordance with the invention, theflange of the cylinder has mounted thereon an abutment having its widthequalling that of one of the recesses of the washer, the latter beingarranged in a groove provided in the housing.

The above specified structure of the arrangement provides for quick andreliable adjustment of the piston stroke in a clutch or a brake of anysize. This has been made possible, owing to the adjustment abutmentbeing situated in the area of the securing bolt and coaxially therewith,which obviates the need in additional bolts and bushes. Furthermore, thewasher itself is received in the groove of the housing of the clutch orthe brake, whereby the dimensions of the latter are reduced.

In accordance with a feature of the present invention, to speed up theadjustment, the abutment is spring-biased to be retained in an adjustedposition. Preferably, the arrangement incorporates several suchadjustment abutments, and the spring is adapted to retain the alreadyadjusted abutment from eventual disengagement thereof from the washer,while the rest of the abutments are being adjusted.

As a rule, in friction clutches and in friction brakes several bolts areused to secure the flange of the cylinder to the housing, thisnecessitating provision of a plurality of the herein disclosedarrangements.

To facilitate the operation and maintenance of the herein disclosedarrangement, each washer is preferably shaped as a polyhedron, the widthof the groove substantially equalling the spacing between the oppositefaces of the washer.

Owing to this construction, all the arrangements situated diametrally ofthe clutch or of the brake are mutually oriented.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood from the followingdescription of an embodiment thereof, with reference being had to theaccompanying drawings, wherein:

FIG. 1 is a longitudinal section view taken along section line I--I ofFIG. 3 and illustrates a piston stroke adjusting arrangement embodyingthe present invention;

FIG. 2 is a section view taken along section line II--II of FIG. 1;

FIG. 3 is a fragmentary end view of the arrangement in FIG. 1;

FIG. 4 is a perspective view of an abutment element in the arrangementaccording to the invention; and

FIG. 5 is a perspective view of a washer in the arrangement shown inFIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, the arrangement embodying the presentinvention includes a housing 1 (FIG. 1) and a flange 2 of a cylinder 3receiving therein a reciprocating piston 4, the housing 1 and the flange2 being rigidly attached to each other. To provide for limiting thepiston stroke, the housing 1 has made therein a groove 5 accomodating awasher 6 with radial recesses 7 of different depths. The flange 2 hasmounted thereon an abutment 8 arranged coaxially with a bolt 9 which isone of the several bolts securing the housing 1 and the flange 2 of thecylinder 3 to each other. The abutment 8 is received in one of theradial recesses 7 and has a width equilling the width of this recess 7,for tight engagement of the abutment 8 and the washer 6. The abutment 8is urged by a spring 10 which is a compression spring having one its endbearing against the end face 11 of the abutment 8 and its other endbearing against an annular shoulder 12 provided in the flange 2.

To retain the washer 6 against rotation in the groove 5 (FIG. 2), thewasher 6 is shaped as a polyhedron, e.g. hexagon, having always its twoopposite faces or sides 13 engaging the lateral sides 14 of the groove5, i.e. the width of the groove 5 substantially equals the spacing ofthe opposite sides or faces 13 of the washer 6.

The washer 6 is additionally provided with lugs 15 retaining theabutment 8 in the adjusted position in the recesses 7 of the washer 6.

As a rule, the flange 2 of the cylinder 3 is secured to the housing 1with a number of bolts 9; therefore, the same number of washers 6 andabutments 8 is preferably used for adjusting the stroke of the piston.

The herein disclosed arrangement is operated, as follows.

The bolt 9 is turned out from the housing 1 of the clutch or of thebrake, as case may be, to an extent that, by having moved the flange 2of the cylinder 3 in the bolt-loosening direction, the abutment 8 may bedisengaged from the washer 6 against the effort of the compressed spring10, and rotated about its own axis for the abutment part 8 thereof to bepositioned to face a deeper recess 7 of the washer 6, i.e. the recess 7which is different from the one selected at the initial adjustment. Thisdone, the abutment 8 is moved toward the washer 6 to engage it in thenow selected recess 7 of the washer 6. While the rest of the abutment8 - washer 6 couples are being adjusted, the spring 10 retains thealready adjusted couples, likewise including each an abutment 8 and thewasher 6. Upon having adjusted in the same manner all thewasher-abutment couples interposed between the housing 1 and the flange2 of the cylinder 3, the flange 2, and hence, the entire cylinder 3, aremoved for the flange 2 to engage the end face 11 of the abutment 8,whereafter all the bolts 9 are tightened. Should it be necessary toremove the worn out friction members and install new ones, following thereplacement, the washer-abutment couples are set at the position of theinitial adjustment, with the abutment 8 engaging the most shallow recess7 to provide for the gap "a " (see FIG. 1).

The herein disclosed arrangement makes additional fastening membersunnecessary and enables to reduce the weight of the piston strokeadjustment means, as well as to make available but a few standard sizesof mass-produced washers to fit various types and dimensions of brakesand clutches.

Washers for arrangements of the herein disclosed kind can be produced bycommonly used machines for cold punching or upsetting.

What is claimed is:
 1. A piston stroke adjusting arrangement fordisc-type brakes and clutches comprising, a cylinder housing having aradial groove on an end thereof having two opposed flat sides, acylinder in said housing, a cylinder end cover closing an end of saidcylinder, a bolt extending through said cover into said housing forremovably securing the flange cover to said housing, a pistonreciprocable in said cylinder, means for varying the clearance betweenthe piston and the cover comprising at least one washer having amultiplicity of paired flat sides for locating it in said groove withopposite flat sides engaging the opposite flat sides of the groove topreclude rotation of said washer in said groove, said bolt extendingaxially through said washer, said washer having a plurality of alikeradial recess of different depth extending radially of said bolt andcoaxial therewith, an abutment member having a through opening throughwhich said bolt extends axially, an abutment projection on a face ofsaid abutment member received in a corresponding one of the recesses androtational about said bolt for selective insertion into differentcorresponding ones of the recesses in said washer, said abutmentprojection having a cross section corresponding with the alike recessesfor being received therein, wherein the clearance between the cover andthe piston is varied in dependence upon into which recess of saidabutment projection is received thereby to set the length of the strokeof said piston.
 2. A piston stroke adjusting arrangement according toclaim 1, in which said cover has a recess coaxial with said bolt andopen to said abutment member, a spring in said recess about said boltbiasing said abutment toward said washer.